HY Zeolite Modified by Liquid Silane Deposition and Its Catalytic Activity in Selective tert-Butylation of Naphthalene

HY zeolites were modified by chemical liquid deposition with i-C₄H₉Si(OC₂H₅)₃, followed by hydrothermal treatment. The samples were characterized by X-ray diffraction, N₂ adsorption and pulse mass analysis to investigate the influence on framework structure, specific surface area, pore diameter and adsorption behaviors. The catalytic performances of HY zeolite and the modified samples in the alkylation of naphthalene with tert-butyl alcohol were also evaluated. The results showed the modification of HY zeolite did not change framework structure but increased specific surface area, decreased average pore diameter, and reduced the size of pore opening. Catalytic activity of the modified HY zeolite catalyst for tert-butylation of naphthalene was decreased compared with that of HY zeolite catalyst while shape-selectivity of 2,6-di-tert-butylnaphthalene (2,6-DTBN) was increased obviously, the highest 2,6-DTBN/2,7-DTBN ratio of 6.62 obtained.     

Synthesis of 9-benzyl-o- and 9-benzyl-m-carboranes containing functional substituents in the benzene ring by electrophilic alkylation ofo- andm-carboranes by the correspondingR-benzyl halides

9-Benzyl-o- andm-carboranes containing NO₂, COOH, COOMe, and COPh groups in thepara-position of the benzene ring were synthesized by the Friedel—Crafts reaction.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1138–1140, June, 1995.This study was financially supported by the International Science Foundation (Grant MSE 000).     

Synthesis of Methyl tert-Butyl Ether from tert-Butyl Alcohol and Methanol Using Beta Zeolite Catalysts

MTBE synthesis from tert-butyl alcohol (t-BA) and methanol has been studied using beta zeolites. Increasing the reaction temperature results in an increase of t-BA conversion with concomittant decrease of MTBE selectivity. The t-BA conversion decreases with increasing calcination temperature and alkali metal ion exchange of H zeolite. The catalytic results are correlated with the surface area and the acidity of catalysts.     

Selective dehydrogenation of isopropyl alcohol on low-percentage supported bimetallic rhenium-containing catalysts

The activity and selectivity of mono-and bimetallic sibunite-supported Re-, Cu-, Ni-, and Pd-containing catalysts in dehydrogenation of isopropyl alcohol to acetone (T=200–275 °C,v=1.1h⁻¹) were studied. The bimetallic Re, Cu-, Re, Ni-, and Re, Pd-catalysts containing 1 or 2% of the metal possess the higher activity and stability than monometallic catalysts. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2381–2383, November, 1998.     

Alkylation of acetylene by tert-butyl alcohol

A reaction of acetylene with tert-butyl alcohol in the presence of sulfuric acid leads to tert-butylacetylene.     

Selective alkylation of phenol with tert-butyl alcohol catalyzed by [bmim]PF6

Alkylation of phenol with tert-butyl alcohol (TBA) in a room temperature ionic liquid, 1-butyl-3-methylimidazoliumhexafluorophosphate ([bmim]PF₆), has been investigated. The effects of various parameters such as reaction temperature, reaction time, reactant ratio (mol ratio of phenol to that of TBA), and the amount of the ionic liquid used were studied. The [bmim]PF₆ ionic liquid was found to catalyze the reaction with high conversion and good selectivity.     

Catalytic oxyfunctionalization of alkanes by manganese and ruthenium clusters

Di- and trinuclear clusters of manganese and ruthenium were used as catalysts in the oxidation of alkanes in the presence oftert-butyl hydroperoxide as oxidant. The investigations reveal marked differences in the reactivity of the manganese and ruthenium catalysts though structurally they have similar coordination environment. The probable mechanism of hydroxylation in these systems is discussed.     

Photochemical and thermal rearrangements of 2-arylamino-1-(4-tert-butylphenoxy)-9,10-anthraquinones

Photochemical transformations of 2-arylamino-1-(4-tert-butylphenoxy)-9,10-anthraquinones involve migration of thetert-butylphenyl group either to theperi-located carbonyl oxygen to give 2-arylamino-9-(4-tert-butylphenoxy)-1,10-anthraquinones or to the nitrogen atom to give 2-aryl(4-tert-butylphenyl)amino-1-hydroxy-9,10-anthraquinones (typical products of the Smiles rearrangement). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2519–2522, December, 1998.     

Hydrogenation on palladium-containing granulated catalysts 3. Synthesis of aminobenzimidazoles by catalytic hydrogenation of dinitroanilines

Efficient hydrogenation of o-aminonitrobenzenes on palladium-containing granulated carbon catalysts in carboxylic acid solutions was accompanied by cyclization into aminobenzimidazoles. A simple hydrogenation reactor with a fixed gauze holding a reusable granulated catalyst was designed. Acylated and sulfonylated 4(7)-aminobenzimidazoles were obtained. In terms of electronic and geometrical parameters, they are close analogs of biologically active imidazo[1,5,4-e,f ][1,5]benzodiazepines. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1171–1181, June, 2007.     

Composition of products and mechanism of the reaction of ozone with 2,6-di(tert-butyl)-4-methylphenol

It was shown that two series of products with opening and with preservation of the aromatic nucleus are formed in the reaction of ozone with ionol, and a mechanism was proposed for the reaction.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117334 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1203–1207, May, 1992.     

Oxidation of secondary terpene alcohols by chlorine dioxide

Secondary terpene alcohols cis- and trans-verbenol, neo-iso-verbanol, borneol, iso-borneol, and menthol were oxidized by chlorine dioxide into the corresponding ketones. It was shown that the nature of the solvent and catalyst and the structure of the starting compound, including the stereochemistry of the hydroxyl, influenced the oxidation process. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 585–587, November–December, 2008.     

Reactions of aminophenols with formaldehyde and hydrogen sulfide

The reaction of m-aminophenol with CH₂O and H₂S (1: 2: 1 ratio) afforded 2, 12-dioxa-4, 14-dithia-6, 16-diazatricyclo[15.3.1.1^7,11]docosa-1(20), 7(22), 8, 10, 17(21), 18-hexaene in ∼9% yield. Aminophenol o-and p-isomers react with CH₂O and H₂S (1: 3: 2) to form 2-and 4-[4H-1,3,5-dithiazin-5(6H)-yl]phenols in 86 and 71% yields, respectively. In the crystal structure of the latter, molecules contain dithiazine cycles in the chair conformation with the axial hydroxyphenyl group. Molecular packing represents a combination of molecules forming chains due to the OH...S intermolecular hydrogen bond. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 305–308, February, 2006.     

Three-component synthesis of 3,4-dihydroisoquinoline derivatives

A simple and convenient method for the synthesis of 1-substituted 3,3-dimethyl-3,4-dihydroisoquinolines was developed. The method is based on the [2+2+2] cyclization of alkyl- or alkoxybenzenes with isobutyraldehyde and nitriles.     

The separation and determination of nitrophenol isomers by high-performance capillary zone electrophoresis

o-Nitrophenol, m-nitrophenol, and p-nitrophenol could well be separated by capillary zone electrophoresis (CZE) by only adjusting the run buffer with methanol. Efficiency up to 10⁵ theoretical plates per meter was achieved. The effects of several important factors were investigated to find optimum conditions. The linear range, regression equation, and the recovery were given. This method possessed the advantages of simplicity, rapidity, and good reproducibility; it can be developed for the separation of practical samples in environment analysis.     

Selective Hydrogenation of Carvone and o-Xylene (cis-trans) on Pd/Y Exchanged Zeolites

o-Xylene and carvone hydrogenation on supported Pd on exchanged Y-zeolites was done. A controlled selectivity of hydrogen stereoaddition (cis- and trans-) in o-xylene and a large control of the multiple hydrogen addition in carvone were obtained. These effects were achieved by controlling the exchanged Y zeolites acidity.     

1-Acyldeoxyvasicinone salts as effective intermediate C-and N-acylating agents for alkaloids and amino acids

The reaction of deoxyvasicinone with acid chlorides of aliphatic (acetylbromide) and aromatic (benzoyl-, o-, p-methoxy-, p-nitrobenzoylchlorides) acids was studied. It was shown that 1-deoxyvasicinone salts were formed at room temperature; α-aroyloxymethylidenedeoxyvasicinones, in the presence of triethylamine at 80–85°C. It was found that acid chlorides cause 1-acyldeoxyvasicinone salts to transform into α-hydroxy-or α-aroyloxyarylidenedeoxyvasicinones, which indirectly confirmed their acylating properties. It was found that 1-acyldeoxyvasicinone salts were effective acylating agents for alkaloids (cytisine, 1,2-dihydrodeoxyvasicinone) and amino acids (glycine, β-alanine, α-aminobutyric acid) and can be used to acylate primary and secondary aliphatic and heterocyclic amines. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 585–589, November–December, 2006.     

Synthesis and characterization of bis(glycosylamino)benzenes based on reducing disaccharides

Synthesis of bis(glycosylamino)benzenes, derived from disaccharides lactose, maltose, and cellobiose, by direct condensation and their characterization are described. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1235–1238, May, 2005.     

Influence oftert-butyl alcohol on cyclodextrin inclusion complexes of pyrene

The effect oftert-butyl alcohol on complexes of pyrene and various cyclodextrins is investigated. The equilibrium constant for the complexation is derived from the fluorescence decay parameters. A greater than twofold enhancement of pyrene lifetime is observed in the presence oftert-butyl alcohol and -cyclodextrin or -cyclodextrin. As the number of hydroxyl groups decreases, substituted -cyclodextrins show smaller enhancements to both the fluorescence lifetime and the formation constant. These observations are explained by proposing that alcohol molecules are associated with the inclusion complex. This association increases the apparent hydrophobicity of the cyclodextrin cavity, protects the molecule from collisional quenching and deactivation, and provides additional rigidity to the system.     

Effects of adsorption-induced microstructural changes on separation of xylene isomers through MFI-type zeolite membranes

Various factors were found to affect the performance of MFI-type zeolite membranes in separating xylene isomers (p-xylene, PX; o-xylene, OX) by pervaporation. In this work the effect of membrane microstructure, membrane quality, and pervaporation operating conditions were investigated using three membrane microstructures: random, c-oriented, and h,0,h-oriented. Operation under pervaporation conditions means that high loadings of PX will be present in the framework; therefore, the role of PX–framework and PX–OX interactions needs to be taken into consideration. Single component experiments demonstrated that the order of experimentation with OX and PX will affect the ideal selectivity. Multi-component studies showed that membrane performance is highly dependent on the relative concentration of the isomers in the feed; the higher the PX concentration the lower the selectivity observed. However, although high selectivity (18) was observed at low PX concentrations in the feed, it was not stable over time. Similar trends were observed for all membrane microstructures but differences in the selectivity values occurred. The structural deformation caused by high loadings of PX into the silicalite crystal affects each microstructure differently, ultimately leading to differences in performance.